A curious new study says that the benefits of the Mediterranean diet only apply to the wealthy, but experts are casting doubt on its findings.

In the Italian study, which was led by Giovanni de Gaetano, researchers discovered that given a similar level of adherence to the diet, the lower cardiovascular risk is only noted in people with a higher household income or a greater level of education. Specifically, the researchers discovered that those participants who had post-high school education or a household income that exceeded $47,000 a year had a 60 percent lower cardiovascular disease risk. Less advantaged groups, meanwhile, did not demonstrate any noticeable benefits.

The researchers measured adherence to the diet in terms of staples like vegetables, fruits and nuts, cereals, fats, fish, legumes, dairy products, alcohol and meat. Within these categories, they found that people who had a higher income or educational level tended to eat individual foods that were richer in polyphenols and antioxidants as well as a greater variety of fruits and vegetables. They also observed differences in the preferred cooking methods used and the consumption of whole-grain products.

For example, more affluent participants ate more fish and organic produce, while their poorer counterparts were more likely to fry food. It could be considered a flaw in the design of the study that the researchers’ Mediterranean diet adherence score did not account for the differences in the quality of food consumed or the way in which it was prepared. It’s only natural that someone who fries any food – even if it’s healthy – will not get the same heart benefits as a person who grills it, for example.

Doubts about the study

While the quality of individual ingredients could well account for some of the difference, it fails to explain the huge discrepancy in effectiveness, casting its findings into doubt. While the researchers took into account factors like body mass index and marital status, some experts believe that other differences between the high and low income groups must explain why the diet was less effective for poorer people. After all, food does not know your income and apply its benefits discriminately. What about the fact that wealthier people tend to have better healthcare and better access to healthy foods in general, for example?

Cardiovascular expert Dr. Tim Chico of the University of Sheffield said that this study confirms what has long been known: Those with lower income or education levels have twice the risk of heart disease of those who have higher income and education. He believes the differences can be ascribed to other factors beyond the diet, and emphasizes that the findings should not discourage anyone from following the Mediterranean diet, which remains the best way of eating to reduce one’s risk of heart disease. However, it should be part of a healthy lifestyle overall that focuses on maintaining a healthy weight, exercising regularly and avoiding smoking.

Harvard Chan School of Public Health’s Mercedes Sotos-Prieto, meanwhile, told CNN that the study does not prove that it was the socioeconomic status that caused the health benefits; instead, it merely indicates a relationship that has long been known when it comes to diet quality and income. Other experts caution that the self-reported nature of the study allows for a lot of inaccuracy.

No one can deny that foods like fish, extra-virgin olive oil and organic produce are not exactly cheap, but it is hard to believe that adopting the Mediterranean diet would not benefit those who eat a typical Western diet full of processed foods and sugar.

The study isn’t saying that the Mediterranean diet is bad; it is merely saying that a higher-quality Mediterranean diet is even better for you, which is hardly surprising. Even without the heart benefits, there are lot of other reasons to follow the diet, such as its ability to reduce the risk of dementia by 35 percent, and its benefits for asthma, allergies, arthritis and diabetes.

Those on a tight budget who want to reap the benefits can make their money go further by buying organic fruit and vegetables that are in-season and avoiding overcooking them.